Political type might stop by and behave badly (8)
I believe the answer is:
activist
'political type' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
'might stop by and behave badly' is the wordplay.
I cannot quite understand how this works, but
'behave' could be 'act' (acting is a kind of behaving) and 'act' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for activist that I've seen before include "One who works energetically as in politics" , "Human dynamo" , "Busy worker for cause" , "Advocate for action" , "Vigorous political campaigner" .)